$ df -B 1 /dev/sdc1                                                            
Filesystem     1B-blocks    Used Available Use% Mounted on
/dev/sdc1      501760000 4358144 497401856   1% /media/xieerqi/HEXMEX

$ df -H /dev/sdc1                                                              
Filesystem      Size  Used Avail Use% Mounted on
/dev/sdc1       502M  4.4M  498M   1% /media/xieerqi/HEXMEX